The invention relates generally to air flow control within a closed environment, such as a house or office building. More specifically, the invention relates to and apparatus and method for balancing the air pressure within such an environment.
It is well known in the construction, architectural and interior design industries that enclosed spaces within a building, either of the commercial and residential nature, are susceptible to poor air quality. This is primarily due to lack of good ventilation and air circulation within that space. For example, spaces that are not exposed to good air flow or are exposed to moisture or particulate matter, such as bathrooms, are particularly problematic. As a result, the air quality can become poor that can create unwanted odors, growth of mold, health hazards, and the like.
Today, the air inside most homes is more polluted and unhealthy than outside air at its worst. The way air exchange has been done in the past has been to open windows. However, in today's market it is very costly to leave a window open at times particularly when it's cold or hot outside as this will compete with the heating or air conditioning systems that are operating at the time. Therefore, simply opening a window for ventilation and air circulation is not a viable or desirable option.
A better solution is to improve the airflow within the space and to balance the air pressure in that environment.
Air pressure is one of fundamental living conditions for human beings. Comfortable air pressure is usually about 1 atmospheric pressure at sea level. Tremendous efforts have been devoted to control the interior climate within a building construction, such as temperature, humidity, freshness, and air pressure. However, compared to the control over other parameters, the achievements and applications of control over air pressure within building constructions have been quite limited.
Air pressure control, in comparison with other interior climate control mechanisms, is more difficult for the fact that pressure difference is the direct driving force for air to flow. If the internal air pressure is significantly different from external atmospheric pressure, any direct connection between the internal air and external atmosphere, no matter where it is in the building, may quickly lead air to flow from high pressure regions to low pressure regions and thus to reduce the pressure difference between the internal air and the external air and between rooms of a given building structure. The use of doors, which may be closed to seal off a room, makes it more difficult to balance the air pressure within a building. This situation is further complicated when a return vent is on an opposing side of a closed door where that closed door prevents the return of air to the return vent for intended air circulation. An environment with poorly balanced air pressure will cause the entire HVAC system to suffer from poor performance and poor efficiency because the air handler and other components will be required to work harder to move the air within the space.
There are two basic issues in interior air pressure control. The first is sealing the enclosed airway and the second is keeping the internal air refreshed. For the reason discussed above, without sealing the enclosed airway, air will leak through any kinds of interstices of the building, which makes it very difficult to maintain a significant pressure difference between the internal air and external environment. However, since air cannot freely flow in and out of a fully sealed construction, measures need to be taken to keep the internal air refreshed.
In the past years, air pressure controls have mainly been applied in special restricted areas such as labs exposed to contaminated environment, patient rooms in hospitals that require special prevention of bacteria and other contaminants, or a manufacturing environment where cleaner air is necessary. For these special interests on special restricted areas, air pressure control have typically relied on complicated mechanical control systems to modulate the flow rates constantly in response to pressure fluctuations, which would be quite expensive to implement and maintain on a large scale and for significantly large pressure differences. Residential application of those implementations in territories like high altitude regions, where air pressure control is essentially meaningful to many people, could be too much luxury to be a common practice.
There have been attempts in the prior art to balance the air pressure in rooms that have closed doors. These efforts include jump ducts, air return vents and transfer grills that are installed in ceilings and through walls. These solutions are expensive and cumbersome to install. Also, they are not particularly attractive once installed. Transfer grilles can be very difficult to install, particularly because they are located in the center or middle of a door and not at an edge thereof. Other solutions include under cutting the door, such as much as one foot. For obvious reasons, this solution is typically not acceptable.
With the present invention, the application and maintenance of interior air pressure control systems in building constructions will be much less expensive than the conventional building ventilation systems. This will make residential usage of air pressure control in need become economically practical. Therefore, there is a need for an economical and inexpensive apparatus to facilitate the balancing or equilibrium of air pressure within a building structure. There is a need for an alternative to complicated and expensive air flow systems.